A conventional traveling guide shoe for a roller chain such as, for example, a tensioner shoe or a guide shoe, has a cross-sectional shape which is substantially uniform throughout the whole length of the shoe. The shoe is in pressure-bearing contact with a run of a roller chain throughout the length of the shoe.
For example, FIGS. 4 and 5 show conventional cross-sectional shapes. In the cross-sectional shape of a shoe 1A shown in FIG. 4, a projecting rolling guide surface 2A bears against only rollers R of a roller chain C, and displacement of the chain C is restrained by both side faces of the projecting surface 2A. In the cross-sectional shape of a shoe 1B shown in FIG. 5, a base slide guide surface 2B bears against only the bottom faces of link plates L1 and L2 of the roller chain C, and lateral displacement of the chain C is restrained by a pair of upright guide surfaces 3, 3 projecting upwardly at both side edges of the base surface 2B.
In the prior art shown in FIG. 4, at the incoming end of the shoe 1A, each roller R of the roller chain passes into engagement with the incoming end of the projecting rolling guide surface 2A, thereby causing intermittent striking against the incoming end, and marked wear and deterioration of durability arises. The prior art shown in FIG. 5 also involves the drawback that an increase in the chain traveling resistance caused by a sliding friction of the link plate bottom faces and an increase of sliding wear are unavoidable. As another drawback, the paired upright guide surfaces 3,3 projected on both side edges of the shoe cause an increase in the width of the shoe.